4. Are refractory or relapsed after at least one prior ITP therapy (patients who are refractory and failed to achieve a platelet count ≥ 50,000/mm^3 despite steroids or ≥ 30,000/mm^3 to other prior ITP therapies, such as splenectomy, danazol, or immunosuppressive drugs. For patients who are relapsed, the platelet counts must be below 50,000/mm^3 if using steroids or 30,000/mm^3 if not prescribed steroids.)